Wildfires, high temperatures and light winds have caused air quality in Northern California to deteriorate and prompted Bay Area officials to declare Friday the first Spare the Air Day of the 2013 season.

The region exceeded the health standard for ozone pollution Thursday and is expected to do so again Friday afternoon, according to the Bay Area Air Quality Management District.

Smoke from wildfires in Tehama and Butte counties are contributing to higher than normal particulate matter levels, air quality officials said.

“These high temperatures and smoke from wildfires are creating hazy skies and unhealthy air in the region,” Jack Broadbent, executive officer of the air district, said in a statement.

“It doesn’t take much to cause the region to experience unhealthy air which is why this summer, we are asking residents to leave their car at home at least twice a week — take transit, carpool or bike to work instead of driving,” Broadbent said.

Spare the Air days are normally announced a day in advance, but officials changed today’s forecast in response to the conditions.

Spare the Air alerts are triggered by unhealthy levels of ozone pollution, which can cause throat irritation, congestion, chest pain, asthma and lung inflammation and can worsen bronchitis and emphysema. It is especially harmful to young children, seniors and those with respiratory and heart conditions and can reduce lung function with prolonged exposure.

Residents are encouraged to avoid outdoor activities during the hottest hours of the day and exercise outdoors in the early morning hours.

The 2013 Spare the Air public awareness campaign was launched at the start of May with a focus on solo drivers.

Transportation-related pollution is the region’s largest air pollutant and more than 37 percent of Bay Area employees commute alone to work each day, air district officials said.